scholarly journals Estimates of genetic parameters and genetic trends for reproductive traits and weaning weight in Tabapuã cattle1,2

2015 ◽  
Vol 93 (11) ◽  
pp. 5175-5185 ◽  
Author(s):  
P. A. Bernardes ◽  
D. A. Grossi ◽  
R. P. Savegnago ◽  
M. E. Buzanskas ◽  
I. Urbinati ◽  
...  
Keyword(s):  
Genetic Parameters ◽  
Reproductive Traits ◽  
Weaning Weight ◽  
Genetic Trends

scholarly journals Genetic effects on reproductive traits in Warmblood horses

2009 ◽  
Vol 89 (2) ◽  
pp. 215-218 ◽  
Author(s):  
A. Wolc ◽  
G. Torzynski ◽  
T. Szwaczkowski
Keyword(s):  
Key Words ◽  
Fixed Effects ◽  
Genetic Parameters ◽  
Genetic Effect ◽  
Reproductive Traits ◽  
Additive Genetic Effect ◽  
Reproductive Efficiency ◽  
Horse Breeding ◽  
Estimate Heritability ◽  
Genetic Trends

Reproductive efficiency is an important issue in horse breeding. However, almost no estimates of genetic parameters of reproductive traits in horses can be found in the literature. The objective of the study was to estimate heritability and genetic trends of foaling rate and number of reproductive seasons in Warmblood horses. The records of 3965 mares from six studs were analyzed. Mares were on average kept for 7.3 reproductive seasons with a foaling rate of 66%. Models included fixed effects of stud, period of birth, breed and random additive genetic effect. Heritability estimates were 0.12 for foaling rate and 0.17 for number of reproductive seasons. Key words: Heritability, reproduction, horse

scholarly journals Genetic Parameters, Breeding Values and Genetic Trends for Some Productive and Reproductive Traits of Holstein Cows in Egypt

2019 ◽  
Vol 45 (1) ◽  
pp. 142-154
Author(s):  
Tamer M. Abdel-Hamid ◽  
Khairy M. El-Bayoumi ◽  
Mahmoud S. El-Tarabany ◽  
Wafaa R.I.A. Sherief
Keyword(s):  
Genetic Parameters ◽  
Reproductive Traits ◽  
Holstein Cows ◽  
Breeding Values ◽  
Genetic Trends

scholarly journals Genetic parameters and trends for reproductive traits in Blanco Orejinegro cattle from Colombia

2021 ◽  
Vol 42 (4) ◽  
pp. 2523-2538
Author(s):  
Sindy Liliana Caivio-Nasner ◽  
◽  
Albeiro López-Herrera ◽  
Luis Gabriel González-Herrera ◽  
Juan Carlos Rincón Flórez ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
Genetic Parameters ◽  
Environmental Influence ◽  
Cattle Breed ◽  
Heritability Estimate ◽  
Reproductive Traits ◽  
Genetic Trend ◽  
Genetic Progress ◽  
Estimated Breeding Values ◽  
Genetic Trends

The Colombian creole cattle breed Blanco Orejinegro (BON) is an important zoogenetic resource, but there is little knowledge about the genetic parameters and trends of its reproductive traits. Therefore, the aim of this study was to estimate parameters for the reproductive traits calving interval (CI), age at first calving (AFC), gestation duration (GD) and genetic trends for CI in the BON breed. Genealogy information from 7,799 animals was used, and employing the MTDFREML program, the components of the variance, heritability (h2), repeatability (rep), and estimated breeding values (EBV) for CI (n=3308), AFC (n=729), and GD (n=306) were estimated, in addition to the inbreeding coefficient (F) of the population. Genetic trends were established through linear regression using R software. Finally, the animals were classified as inbred (F > 0) and noninbred (F=0), and the effect of inbreeding on reproductive performance was established through a generalized linear model using the R program. An average F value of 4.41%±0.06 was observed. The h2 for CI was 0.11±0.03 with a rep of 0.15±0.04; for AFC, h2 was 0.00±0.05; and for GD, h2 was 0.00±0.08. The genetic trend for CI was -0.01 days/year. Finally, for CI, inbreeding depression was evident; this trait increased when inbreeding increased. These results indicate an important environmental influence on reproductive traits. The heritability estimate for CI suggests that little genetic progress could be achieved through selection. The evidence of inbreeding depression raises the need to control inbreeding to conserve this genetic resource.

scholarly journals Estimation of genetic parameters and genetic trends for reproductive traits in Saanen goats

2013 ◽  
Vol 63 (2-3) ◽  
pp. 269-277 ◽  
Author(s):  
A. Kasap ◽  
B. Mioc ◽  
D. Skorput ◽  
Vesna Pavic ◽  
Z. Antunovic
Keyword(s):  
Genetic Parameters ◽  
Reproductive Traits ◽  
Estimation Of Genetic Parameters ◽  
Genetic Trends

scholarly journals Genetic parameters, genetic trends, and principal component analysis for productive and reproductive traits of Guzera beef cattle

2019 ◽  
Vol 48 ◽  
Author(s):  
Nicole Colucci Tramonte ◽  
Natalia Vinhal Grupioni ◽  
Nedenia Bonvino Stafuzza ◽  
Diego Gomes Freire Guidolin ◽  
Rodrigo Pelicioni Savegnago ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
Beef Cattle ◽  
Genetic Parameters ◽  
Principal Component ◽  
Reproductive Traits ◽  
Component Analysis ◽  
Genetic Trends

Estimation of Genetic Parameters and Selection Response for Reproductive and Growth Traits in Rideau-Arcott sheep

2020 ◽  
Author(s):  
Mohammed Naser Boareki ◽  
Luiz Brito ◽  
Angela Cánovas ◽  
V.R. Osborne ◽  
Flavio S Schenkel
Keyword(s):  
Litter Size ◽  
Genetic Parameters ◽  
Growth Traits ◽  
Reproductive Traits ◽  
Selection Response ◽  
Direct Selection ◽  
Correlated Response ◽  
Response To Selection ◽  
Weaning Weight ◽  
Selection For

The goal of this study was to estimate genetic parameters and predict direct and correlated response to selection for lamb growth traits and ewe reproductive traits, based on single trait selection or combining multiple traits in an optimum index that targets total litter post-weaning weight in the first lambing as the main selection goal. Heritability estimates ranged from 0.04 to 0.19. Genetic correlations between growth and reproductive traits ranged from -0.24 to 0.15. The indirect response to selection for reproductive traits in later lambings, by selecting on first lambing performance, was 11 to 25% greater than direct selection. The response to indirect selection for composite reproductive traits, i.e. total weaning weight or total post-weaning weight, by selecting on individual lamb weaning weight or post-weaning weight was 1 to 69% greater than direct selection, but it was accompanied by a negative response on litter size. However, combining alternate growth and reproductive traits in optimum selection index resulted in correlated response of up to 96% greater than direct selection response for reproductive traits without a negative response on litter size. Therefore, multiple trait selection using an index of component traits was more effective than direct selection for a composite trait.

Investigation of genetic variability and inbreeding characteristics in a population of Zandi sheep

2008 ◽  
Vol 88 (3) ◽  
pp. 409-417 ◽  
Author(s):  
Farhad Ghafouri-Kesbi ◽  
Moradpasha Eskandarinasab ◽  
Ahmad Hassanabadi
Keyword(s):  
Birth Weight ◽  
Genetic Parameters ◽  
Breeding Value ◽  
Effective Population ◽  
Genetic Progress ◽  
Weaning Weight ◽  
Average Value ◽  
Estimated Breeding Values ◽  
Genetic Trends ◽  
Zandi Sheep

The aim of the present study was to evaluate the genetic parameters and genetics trends for birth and weaning weights, and to quantify the inbreeding characteristics for a population of Zandi sheep. Genetic parameters from both single- and two-trait analyses were estimated using restricted maximum likelihood (REML) with animal models. Genetic trends were estimated by averaging estimated breeding values on year of birth. Full pedigree was analyzed for estimation of inbreeding characteristics. The results obtained confirmed relatively low additive genetic variation in the population, especially for weaning weight. Estimates of direct and maternal heritability were 0.12 and 0.20 for birth weight and 0.08 and 0.02 for weaning weight, respectively. Estimates of breeding value averaged by year of birth for birth weight and weaning weight increased over time. However, there was little genetic progress for birth weight (0.002 kg yr-1), whereas the tendency for weaning weight was 0.020 kg yr-1. Inbred animals consisted of 25% of the population. The effective population size (Ne) was 66 individuals. The inbreeding rate per generation (ΔF) was 0.76%. The average value of inbreeding (F) in the Zandi population was 1.05% and the average relatedness (AR) coefficient reached 1.64% in the whole pedigree. A range of 2.84 to 4.01 yr was obtained for the average generation interval in different pathways. Selection of rams with the lowest AR was recommended for better management of inbreeding and avoidance of relative mating. Key words: Sheep, genetic trends, heritability, inbreeding, average relatedness

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